Sheet metal building



Nov. 18, 1969 I J. R. POYTON 3, 3

SHEET METAL BUILDING Filed July 6. 1967 '7 Sheets-Sheet 1 F D D Cl D M W L h. 5 5 E5 :1 5 W -37 '---I7 .--l7 /5 a a 5% 5 t E r I V 3 a j N W 7/ A 1/ L I FIG. 2.

l9 l8 I7 FIG. 3.

INVENTOR 2 JOSEPH R. POYTO/V ATTORNEY FIG. I.

Nov. 18, 1969 J. R. POYTON 3,478,477

SHEET METAL BUILDING Filed July 6, 1967 7 Sheets-Sheet 2 INVENTOR JOSEPH R. POYTON ATTORNE Y Nov. 18, 1969 J. R. POYTON SHEET METAL BUILDING 7 Sheets-Sheet 5 Filed July 6. 1967 INVENTOR JOSEPH R. P0) TON ATTORNEY Filed July 6. 1967 Nov. 18, 1969 J. R. POYTON 3, 77

SHEET METAL BUILDING 7 Sheets-Sheet 4 INVENTOR JOSEPH R. P0 YTO/V ATTORNEY Nov. 18, 1969 .1. R. POYTON SHEET METAL BUILDING '7 Sheets-Sheet 5 Filed July 6, 1967 INVENTOR JOSEPH R. POYTO/V $7 ATTORNEY Nov. 1 8 1969 I R; POYTON 3, 77

SHEET METAL BUILDING I Filed July 6. 1967 7 sh t s t 6 J INVENTOR 1 .{11 JOSEPH R. POYTO/V ATTORNEY Nov. 18, 1969 J.- R. POYTON sum METAL BUILDING 7 Sheets-Sheet 7 Filed July 6. 1967 INVENTOR ATTORNEY United States Patent 3,478,477 SHEET METAL BUILDING Joseph Roy Poytou, West Flamborough, Ontario, Canada Filed July 6, 1967, Ser. No. 651,534 Int. Cl. E04b 7/04, /48, 5/10 U.S. Cl. 52-220 8 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a prefabricated sectional steel building.

In the art of the fabrication of buildings of steel, it has generally been customary to provide a framework of steel girders or the like upon which the sheet metal was erected and attached in position. This form of construction is suitable for industrial building but is generally speaking unsuitable for erection of domestic building and temporary or short term housing. Obviously, it is desirable to dispense 'with the use of costly steel girders and to fabricate the entire building of sheet metal providing sufficient rigidity by the design and construction of the sheet metal members and at the same time providing inner and outer wall surfaces to provide a high degree of heat insulation and dry wall construction. In addition to these factors however, it is also desirable that the use of special fastening devices should be reduced to a minimum since they obviously require registration with openings and delay the erection of the building while the fastenings are secured and tightened down. To overcome this problem it is provided in the invention that sheet metal members shall as far as possible be interfitting and interlocking with one another whereby to eliminate the need for additional fastening means.

It is therefore a general objective of the invention to provide a sheet metal building construction in which major portions of inner and outer wall portions of the building are formed of sheet metal and in which the load bearing portions of the structure are also formed of sheet metal.

It is a further objective of the invention to provide a sheet metal building structure in which the various sections of sheet metal can be associated and fastened together by interlocking means with a minimum of fasteners.

More particularly, it is an objective of the present invention to provide a sheet metal building structure having the foregoing advantages in which the sheet metal structure incorporates electrical and air ventilation ductmg.

The invention seeks to provide the foregoing and other advantages which will become apparent from the following description of a preferred embodiment of the invention by the provision of a sectional sheet metal building structure comprising vertical 'wall sections of sheet metal, said vertical sections having an inner wall forming portion and at least one spacing web portion extending normal thereto; interlocking means formed on said spacer web members; horizontal outer wall sections, said outer wall sections having outer wall portions and supporting web portions extending therefrom normal thereto; interlocking means on said supporting web portions; floor forming sections; supporting web sections extending normally from said floor forming sections; interlocking means on said web portions; attachment members formed on said floor portions for attachment of flooring planks thereto; roof forming sections; supporting web members extending normally from said roof forming sections; and interlocking means on said supporting web means.

The preferred embodiment of the invention will now be described with reference to the following drawings in which like reference devices refer to like parts thereof throughout the various views and diagrams and in which;

FIGURE 1 is a perspective view of a building structure according to the present invention and showing a pre ferred form of the invention;

FIGURE 2 is a view in the direction of the arrow 2 shown in FIGURE 1, and shows the wall structure with the outer siding removed;

FIGURE 3 is a section along the line 33 of FIG- URE 2;

FIGURE 4 is an enlarged perspective view of a portion of the wall structure shown in FIGURE 2 and FIG- URE 3 and illustrates the manner in which the inner and outer wall panels are secured to the upright members and the manner in which the upright members are secured to the transverse members;

FIGURE 5 is a perspective view of an alternative form of upright member used in the construction as illustrated in FIGURE 4;

FIGURE 6 is a section along the line 6-6 in FIG- URE 1 and illustrates an alternative form of exterior wall which may be utilized in certain portions of the building structure;

FIGURE 7 is an enlarged end elevation of the roof structure and attachment thereof to the wall structure of the building and shows portions of the wall and roof structure cut away to reveal details of attachment;

FIGURE 8 is an enlarged perspective of a portion of a roof panel or shingle member and illustrates the trough means reproduced in plurality therealong for the purposes of stiffening to aid in water run-off;

FIGURE 9 is a section along the line 99 in FIG- URE 7;

FIGURE 10 is an enlarged perspective view of a portion of a floor structure for use with the building struc ture illustrated in FIGURE 1, and is shown partly in phantom and partly broken away to illustrate features of the construction and attachment;

FIGURE 11 is an enlarged perspective view of the fastening means for securing the flooring members to the floor structure as illustrated in FIGURE 10;

FIGURE 12 is an elevation view of an alternative form of fastener to that as illustrated in FIGURE 11;

FIGURE 13 is an enlarged view of details of the ridge P FIGURE 14 is an enlarged view of the method of attaching the roof rafters to the ridge pole;

FIGURE 15 is an exploded perspective illustration of a further embodiment of the invention, partially in phantom, showing the lower 'wall and floor region;

FIGURE 16 is an exploded perspective illustration of the floor joist and beam construction cut away to reveal the construction;

FIGURE 17 is an enlarged sectional illustration of an embodiment of floor plank clip for use with the embodiment of FIGURE 16,

FIGURE 18 is an exploded perspective illustration of the embodiment of FIGURE 15, partially in phantom, showing the upper wall and roof region, and

FIGURE 19 is a perspective illustration of a further alternative stud section.

Referring to FIGURE 1 a building structure is illustrated and indicated generall as 10. The building structure is provided with a wall structure 11, roof structure 12, and floor structure 13, built up of interlocking pieces and interlocked to provide the complete building structure 10. An alternative form of wall structure 14 is also utilized.

Referring to FIGURE 2, FIGURE 3, and FIGURE 4, details of a typical wall structure are shown. The wall structure 11 comprises upper plate 15 extending transversely along the wall, lower plate 16 also extending transversely along the wall, both plates 15 and 16 being interconnected and spaced apart by means of the vertical stud members 17.

The stud members 17 have a generally rectangular crosssection and being of open channel form are provided with the flanges as at 18 and 19 along the inwardly facing edges. The flanges 19 are utilized for securing the inner wall panels 20 to the studs 17, this being done by means of the locking strips 21 hooking as at 22 onto the flange 19 and having a T section 23 therealong engageable with grooves 24 within the wall panels 20.

The outer wall panels 25 are secured to the upright stud members 17 by means of the formed lip 26 engaging with the tabs 27 formed in position along the length of stud member 17. Upon the wall panels 25 being placed in position to have the lip 26 engageable with the tab 27 the individual wall panels 25 are locked in position by pushing out the tabs 28 formed in the face of stud member 17 thus to prevent upward movement of the panel 25 and to hold same securely in place. The wall panels 25 are also provided with the upwardly projecting lip 29 formed along the lower inner edge thereof which is engageable with the downwardly formed lip 30 formed along the upper outer edge in order that successive wall panels can be secured together.

The upper plate 15 is provided with notches as at 31 and 32 co-operable with matching notches 33 and 34 in the upper edge of stud member 17 to secure the stud member 17 and upper plate 15 from relative lateral movement. A tab 35 is provided on the upper edge of stud member 17 and projects through the notch 32, whereafter it can be bent over to secure the plate member 15 securely to the stud member 17. It should be understood that the attachment means illustrated in FIGURE 4 and previously described is typical for the entire length of the wall section 11, and that similar methods of attachments and securing are utilized throughout the entire structure, that being disclosed being done so by way of example to be utilized wherever similar members are joined.

The lower plate member 16 which is secured to the floor structure as at 36 is utilized in securing the lower end of stud member 17 is a manner similar to the attachment of upper plate 15. Similar mating notches and tabs are provided at this juncture whereby relative lateral movement of the studs 17 and plate 16 is prevented and where the studs 17 are held down on to the plate 16, the latter being secured to the floor structure 36.

The corner construction for the wall portions 11 is shown in FIGURE 3 wherein the corner members 37 is provided. The attachment of the upper and lower plates to the corner member 37 is similar to that as shown for the stud members 17 and for this reason no further detail is shown. In this case both upper plates and both lower plates are secured to the corner member 37 as are the outer wall panels 25. In this manner a secure corner joint is obtained, securely fastening the wall sections together.

Referring to FIGURE 5, an alternative form of stud member is illustrated wherein the vertical stud member 38 is shown of box like configuration. In this embodiment the upper plate 39 is secured to the stud member 38 by means of the pin 40 which is engageable with the slot 41 in the tab 42 of stud 38 upon the tab 27 projecting through the slot 43 in plate 39. In this case the pin 40 is slideably secured to the plate 39 by means of the pin 44 positioned in a slot in the plate 39. The T sections 45 is provided for connecting the wall panels to the stud member in the manner as shown in FIGURE 4.

Referring to FIGURE 6 and FIGURE 7 further details of the wall portion 14 are illustrated. In the embodiment the outer wall panels 46 are provided with upright flanges 47 formed down one side and inverted V flanges 48 formed down the other side so that the upright flange 47 hooks beneath the V flange 48 in the manner as shown at 49, whereby a weather proof joint is obtained. The wall panels 46 are secured to the upright members 50 which are similar in construction to the stud members 17, the fastening means being similar to the tabs 27 shown in FIGURE 4 and these being located at the points 51 and 52 in FIG- URE 6. The wall panels shown at 53 are similar to the inner wall panels 20 shown in FIGURE 4.

Referring to FIGURE 7, FIGURE 8, and FIGURE 9 details of the roof structure 12 are illustrated. The roof structure 12 is provided with a purality of roof rafters 54 which as shown in section in FIGURE 9 are similar to the upright studs 17 illustrated in FIGURE 4. The rafters 54 are spaced along the length of the building along both sides to meet in the ridge pole at 55 as shown in FIGURE 1. The rafters 54 support of the roof panels 56 thereon, these panels being similar in constuction to the wall panels 25. Each roof panel 56 is provided with plurality of drainage channels 57 across the width and spaced apart along the length thereof. As shown in FIGURE 8 the channels 57 are provided at the upper end at 58 with an extension 59 which on assembly projects underneath the lower end of the trough 57 of the upper adjacent roof panel in order that rain from the upper panel will be guided into the lower channel.

The individual panels are secured to the rafters 54 by means of a lower lip 60 engaging with the clips 61 secured to the rafter 54. A lower flange 62 is provided along the bottom of the rafter 54 and the first roof panel 56 is secured as indicated at 63 by means of the gripping lip 64 engaging with the transverse lip 62 on the rafter. The upper end of the panel is secured to the rafter by the clip 61 and the subsequent roof panels 56 are secured as at 65 wherein the gripping lip 64 is secured by the upper projecting lips 66 along the upper edge of the panel 56. This method of securing and laying the roof panels 56 in position is continued until the last panel is in place and secured along the ridge pole 55. A capping strip 67 is fitted over the abutting ends of the upper most panels on both sides of the roof and secured by means of the lips 66. End strips 68 as shown in FIGURE 9 and FIGURE 7 are threaded over the ends of the roof structure to cover in the exposed ends of the roof panels and to complete the roof structure.

Referring to FIGURE 10 and FIGURE 11 details of the floor structure 13 are illustrated. The floor structure 13 comprises a beam member 69 or box like configuration and being provided with internal stiffening means 70 and 71. The box beam 69 is provided with a side mounting flange 72 and lower extension 73. A channel strip 74 is secured to the angle 72 and extension 73 by means of the bayonet type lock indicated at 75. A similar structure is provided at 76 along the length of the box beam and on the other side thereof.

A number of floor joists 77 are supported on the box beam 69 by means of the external structure of the flange 72 and channel 74, Each joist 77 is provided with a flat portion as at 78 and a channel section 79, which is provided with a downwardly depending lip 80 along the edge of the flat section 78 and an upwardly turned gripping means 81 along the length of the channel portion 79. The floor joists 77 are assembled side by side with the lip 80 fitting into the gripping means 81 of adjacent joists to provide a sub-structure for the finished flooring. Spacing means in the form of channel members 82 are provided across and along the length of the box beam 69 whereby the total height of the beam 69 matches the total height of the joist sections.

Each channel section 79 of the joists 77 is provided with a shallow channel member 83 secured along both edges of the channel 79 and provided with a overhanging portion 84 along the length of the gripping means 81. In addition to providing strengthening means for the floor joists 77 the shallow channel 83 also provides means for anchoring the finished floor to the sub-floor. As shown in FIGURE 11 a pointed clip 85 is provided with a hook portion 86 which slideably engages within the gripping means 81 and is secured therein by means of the overhanging portion 84 and is utilized for securing the finished flooring 87 by penetration of the point 88 into the material of the finished floor. The right angle flange 89 on clip 85 bears upon the fiat surface of flange 84 and supports the clip in an upright position ready for driving the point 88 into the finished flooring.

Referring to FIGURE 12 an alternative form of clip is shown wherein the clip 90 has the flange 91 formed similar to that as shown in 89 and is utilized in securing the flange 80 of flat portion 78 in engagement with the gripping means 81. In other respects the clip 90 is similar to the clip 85.

Referring to FIGURE 13 and FIGURE 14 further details of the ridge pole construction are shown. From the drawings it will be seen that the ridge cap 67 is provided with a vertical stiffener 93 which rests within the centre V of the ridge pole 92, The pole 92 extends the length of the building and supports the roof rafter there on as shown in FIGURE 14. Each of the rafters is se--- cured to the ridge pole 93 by means of the clip 94 extending through ridge pole 93 and into lockable engagement with the slots 95 cut into the end 'of the individual rafters.

In use a building structure can be provided according to the foregoing disclosure and the double wall construction utilized throughout the construction of the building can be utilized for the installation of heating, plumbing, and electrical services. Thus the joists members 17 provided within the wall structure 11 can be utilized as means for hot air heating, and the floor structure as provided in the beam 69 and channel portions 79 can be utilized for electrical and plumbing conduits. Since the structure is entirely of metal, fastening of the various services is easily accomplished by the use of sheet metal screws and the like and the services are held securely in place.

The wall structure being provided with an inner and outer wall, can be utilized as insulation means by providing insulation blankets within the double wall structure, the insulation being of a composite nature such as for instance, glass wool together with reflective surfaces, or simply in the form of glass wool alone or otherwise lightly packed within the spaces provided between inner and outer wall. In addition the floor can also be insulated if so desired, spaces being provided in the joists into which suitable insulation can be placed. In sulation also can be provided in the roof structure, secured by conventional means into the spaces between the rafters 54.

With further reference to FIGURE it will be seen that the beam structure 69 can be utilized as a warm air supply duct and in this case the individual joists as provided by the shallow channel 83 and the channel 79 can be utilized as distribution ducts leading from the main supply duct of the beam 69. In this case a slider panel 96 can be mounted along the side of the beam 69 and provide an opening as at 97, whereby the air from the supply duct can be metered into the distribution duct. In this manner a distribution duct can be selected at random along the length of the main supply duct by merely selecting a particular joist structure for use as the distribution duct.

According to a further embodiment of the invention substantial economies may be made by utilising a stud which may also be used as a floor joist, and a roof rafter, while incorporating less steel in a more advantageous section.

FIGURE shows a wall stud 100 having a more or less egg-shaped, oval, tubular section consisting of two sheets of steel formed to provide folded welts 101 and 102. The stud is attached to a lower rectangular frame member 103 at the usual spaced intervals, namely about sixteen inches. Frame 103 is formed into a channel section having inturned lips 104, and lower flanges 105 on its underside. Each stud 100 is provided with two sliding clip fasteners 106 at its lower end loosely riveted by rivets 107 thereto and having slots 108 therein. Spring clips 109 are struck out from either side of fasteners 106 and are oriented to engage with lips 104.

Studs 100 are provided with angled notches or slots 110 arranged at intervals along welts 101 thereof for attachment of outer wall panels 111 thereto. Studs 100 are further provided with beads 112 along Welts 102 thereof for attachment of the interior wall board panels 113 thereto.

Studs 100 are attached at their upper ends to a generally similar channel section frame member 114 having inturned lips 115. Slide fasteners 116 are attached by loose rivets 117 to studs 100 and are adapted to slide in slots 118. Spring clips 119 are struck out from either side of fasteners 116 for engagement with lips 115.

The outer wall panels or sidings 111 are formed of an outer sheeting of sheet metal shaped to fit around a section of insulation board 120 and provided with a lower retaining slot 121 and upper retaining lip 122 engaging with the slot 121 of the next adjacent siding 111. Lip 122a is provided on frame member 103 to hold the lowermost siding 111. Retaining flange 123 is formed along the inner side of siding 111 for engagement with notches 110 on studs 100.

The inner wall board panels or sheets 113, which may be of any suitable plaster board sheet for example, are attached and supported by means of a continuous snap-on clamp member 124 adapted to receive the borders of two adjacent sheets 113, and having a clip portion 125 shaped to fasten around bead 112 of stud 100. Bead 112 is additionally provided with continuous lip 126 for co-operating with clip portion 125. The arrangement of the floor joists and covering is shown in FIGURES 15 and 16.

A floor side-beam 127 which may constitute basic frame of the structure laid upon the foundations is of hollow box-like construction for providing heating ducts andthe like and is provided with jaw members 128 adapted to spring apart and clamp around lower flanges 105 of frame 103. Spaced holes are formed in one side of beam 127 shaped to receive joists 129 therein. Joists 129 are of substantially the same cross-section as studs 100 and are provided with a bead 130 for attachment of the floor covering thereto. One or more intermediate beams 131 also of box-like cross-section are provided for supporting joists 129 and are provided with two or more ducts for heat circulation as in beams 69. Joists 129 are provided with interlocking attachment means at each end comprising slide plate 132 and abutment plates 133 for securing same to beams 127 and 131. Heat circulation is conducted through joists 129 and a series of outlets are provided as by crossmember 134 communicating with joists 129 and having slotted opening 135 therein.

In order to secure a floor covering such as plywood sheets 136 there is provided a continuous snap-on clamp member 137 (see FIGURE 18) of L-shaped section adapted to interfit with notched edges 138 of sheets 136 as shown and hold the same down in position. Clamp members 137 are provided with clip portions 125 identical to those of clamp members 124, shaped to fit around lip 139 of bead 130.

The arrangement of the roof trusses and rafters is shown in FIGURE 17.

A roof truss 140 consists of a section similar to stud 100 and is provided at each end with a fish plate 141 slotted at 142. Roof truss 140 is attached to upper wall frame 143 having lips 144 which consists of a channel section identical to and back to back fastened with frame member 114, by means of slide fasteners 145. Fasteners 145 are attached by loose rivets 146 and are adapted to slide by means of slots 147. Spring clips 148 are formed in each side thereof oriented to engage inturned lips 144 of frame 143. It will be understood that frame 143 is provided with spaced apart shaped cut out sections for receiving the butt ends of trusses 140 as shown.

A roof rafter 149 consists of a section similar to stud 100 and having an upper welt 150 provided with notches or slots 151. A lower fish plate 152 is attached to rafter 149 having a rivet 153 fastened therein for engagement with slot 142 in plate 141. An upper fish plate 154 is attached to rafter 149 having a slot 155 formed therein for interengagement with ridge pole member 156.

The roof is covered with a series of roofing tile members 157 similar to Wall siding members 111 and having lower longitudinal retaining slots 158 and upper retaining lips 159 interchangeable with one another. Retaining flange 160 is provided on the inner side of the tile members 157 for engagement with notches 151 on welts 150 of rafters 149. The transition from Wall to roof is provided by cornice member 161 having a lower retaining slot 162 and an upper retaining slot 163 set at an angle to interengage with the lowermost tile member 157. Tabs 164 are struck out of upper frame 143 to lock cornice member 161 in position.

According to the embodiment of FIGURE 19 a further alternative form of stud is shown as 165 comprising two identical semi-oval portions 165a and 165b which are adapted for forming by simple roll-forming techniques and are provided with peripheral welts 166. Tongues 167 and mating slots 168 are formed in welts 166 and by means of interlocking thereof, and clamping tongues 167 over against welts 166 a strong rigid stud is formed of a generally egg-shaped section, with great economy in tooling, manufacturing time and materials. In order to attach outer wall panels 111 thereto, stud 165 is further provided with out-turned T-shaped flanges 169 along the outer edges of welts 166, having struck out hook portions 170 formed therein for interengagement with panels 111.

The erection and assembly of the various parts of this embodiment Will be apparent from the foregoing description and it will be understood that various services may be incorporated in the section of the building either during manufacture or erection and that the building can in most cases be erected and dismantled in a few hours by unskilled labour with a minimum of tools or special equipment. The building when erected will be strong and serviceable with out the need for special fastenings, and the individual parts thereof can readily be manufactured on simple equipment with only rudimentary tooling.

It Will be further understood that although specific embodiments of the invention have herein been described and illustrated, the invention also contemplates such variations as may fall within the scope of the appended claims.

What I claim is:

1. A sectional sheet metal building structure comprising: vertical wall support stud members of sheet metal; at least one web portion extending outwardly therefrom with respect to the building interior; interlocking notch means formed in said web portions of said stud members; horizontal outer wall covering sections; outer wall supporting web portions extending from said covering sections normal thereto; interlocking flange means on said supporting web portions for engagement with said notch means; floor forming stud members; web portions extending upwardly and downwardly from said floor forming stud members; enlarged bead means on said floor web portions; attachment members connectible with said bead means for attachment of flooring planks thereto; roof forming support stud members; at least one web member extending upwardly from said roof forming stud members; interlocking notch means on said web members extending from said roof stud members; transverse outer roof covering sections; roof covering supporting web portions extending from said covering sections; interlocking flange means on said supporting web portions for engagement with said notch means in said roof stud web means; said stud members in the floor, walls and roof of said building consisting of, two sheet metal wall portions of semi-oval shape in sections, and, welt means joining said wall portions together at each end of said oval and forming a composite web portion therealong.

2. A sectional sheet metal building structure as claimed in claim 1 wherein said horizontal outer Wall sections include inwardly depending flanges to define a space therebetween, and insulation inserted Within this space.

3. A sectional sheet metal building structure as claimed in claim 1 wherein the floor of said building includes at least one beam structure, said structure being hollow in configuration, and joist members extending from said beam members being also of a hollow configuration, and means for selectively ducting heating air from said beam member through said joist members.

4. A sectional sheet metal building structure as claimed in claim 1 wherein said floor and wall stud members comprise;

two sheet metal wall portions of semi-oval shape in section, welt means joining said wall portions together at each end of said oval and forming said web portion thereon, enlarged bead mean formed on one of said web portions along the length thereof extending inwardly with respect to said building interior, and interlocking flange means formed lengthwise along said bead means.

5. A sectional sheet metal building structure as claimed in claim 1 including Wall, floor and roof frame members attached to the ends of respective said supporting stud members for locating same in parallel spaced apart location.

6. A sectional sheet metal building structure as claimed in claim 1 wherein said floor support sections are connected to a hot air circulation system and form part of the air circulation conduit thereof, and including hot air outlet register means connected to said floor support sections.

7. A sectional sheet metal building structure as claimed in claim 1 including enlarged bead means formed along said wall stud members and directed inwardly with respect to said building and wall board attachment clips interengageable with said bead means.

8. A sectional sheet metal building structure as claimed in claim 1 including floor, wall and roof support frame members, and slidable attachment clamping members on the ends of said stud members for fastening the same thereto.

References Cited UNITED STATES PATENTS 1,974,767 9/ 1934 Clark 98-31 2,007,354 7/1935 Vass 52-588 2,058,386 10/1936 Parsons 52-481 X 2,098,752 11/1937 Miller 52-731 X 2,109,655 3/1938 Sylvan 52-481 2,616,529 11/1952 MacDonald 98-31 2,877,990 3/1959 Goemann 52-221 X 3,055,460 9/1962 Maroney 52-241 X 3,280,530 10/ 1966 Rothenbach 52-220 X 3,345,787 10/ 1967 Busscher 52-220 X 3,380,214 4/1968 Stevens 52-90 X FOREIGN PATENTS 501,606 4/1954 Canada.

151,352 5/ 1920 Great Britain.

538,373 1/ 1940 Great Britain.

787,565 12/1957 Great Britain.

FRANK L. ABBOTT, Primary Examiner J. L. RIDGILL, JR., Assistant Examiner US. Cl. X.R. 

